Determination of the Beta Ray Energy Spectrum from the Absorption Curves of Beta Rays

<p>(a) The decrease in food-discovery time between the first tests on two successive days; (b) the positive correlation between colony size and the number of workers searching (mean values for the first tests on the two successive days are presented). The asterisk indicates a significant difference.</p

The Effects of Temperature and Diet during Development, Adulthood, and Mating on Reproduction in the Red Flour Beetle

<div><p>The effects of different temperatures and diets experienced during distinct life stages are not necessarily similar. The silver-spoon hypothesis predicts that developing under favorable conditions will always lead to better performing adults under all adult conditions. The environment-matching hypothesis suggests that a match between developmental and adult conditions will lead to the best performing adults. Similar to the latter hypothesis, the beneficial-acclimation hypothesis suggests that either developing or acclimating as adults to the test temperature will improve later performance under such temperature. We disentangled here between the effect of growth, adult, and mating conditions (temperature and diet) on reproduction in the red flour beetle (<i>Tribolium castaneum</i>), in reference to the reproduction success rate, the number of viable offspring produced, and the mean offspring mass 13 days after mating. The most influential stage affecting reproduction differed between the diet and temperature experiments: adult temperature vs. parental growth diet. Generally, a yeast-rich diet or warmer temperature improved reproduction, supporting the silver-spoon hypothesis. However, interactions between life stages made the results more complex, also fitting the environment-matching hypothesis. Warm growth temperature positively affected reproduction success, but only when adults were kept under the same warm temperature. When the parental growth and adult diets matched, the mean offspring mass was greater than in a mismatch between the two. Additionally, a match between warm adult temperature and warm offspring growth temperature led to the largest offspring mass. These findings support the environment-matching hypothesis. Our results provide evidence for all these hypotheses and demonstrate that parental effects and plasticity may be induced by temperature and diet.</p></div

(a) The effect of the mating/offspring growth diet on mean larval mass. (b) The interaction between parental growth (X axis) and adult diets (left-dark and right-bright columns represent yeast-poor and yeast-rich diets, respectively) on mean larval mass.

<p>Means ± 1 SE are presented. Offspring grown under the rich-yeast diet are larger. A match between the parental growth and adult diets also leads to larger offspring. In spite of the statistical significance, groups did not differ from each other according to a Tukey's post-hoc test because of the small differences between group means and owing to the correction for multiple testing.</p

Results of the temperature and diet experiments supporting either the silver-spoon hypothesis (SSH) or the environment-matching hypothesis / beneficial acclimation hypothesis (EMH/BAH).

<p>Results of the temperature and diet experiments supporting either the silver-spoon hypothesis (SSH) or the environment-matching hypothesis / beneficial acclimation hypothesis (EMH/BAH).</p

Adult (a) and parental growth (b) temperatures had a positive effect on the number of viable offspring produced. Adult (c) and parental growth (d) temperatures had a positive effect on the mean larval mass.

<p>Means ± 1 SE are presented. Asterisks denote significance level (* P < 0.05; *** P < 0.0001).</p

A scheme of the experimental full-factorial design of the diet experiment.

<p>Flour beetles were raised under higher and lower temperature (34°C and 26°C) and yeast-rich and yeast-poor diet (10% and 1% yeast) for 16–23 days till pupation (for exact larval stage duration see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0136924#sec002" target="_blank">Methods</a>). They were then kept under the same conditions or switched upon pupation to the opposite conditions for 12–14 days, and then crossed again between these two conditions for mating, resulting in eight treatment combinations. Offspring were raised under their parents' mating conditions. They were counted and weighed 13 days after the parental mating. Both diet and temperature experiments are similarly designed, with "High" = the 34°C or yeast-rich diet, and "Low" = the 26°C or yeast-poor diet, as the two parental growth, adult and mating/offspring growth conditions.</p

The effect of the time interval (in days, horizontal axis) between tests on the difference between food-discovery time before and after this interval (Δ discovery time, vertical axis).

<p>Values above zero indicate that colonies reached the food reward faster after the time interval than before it, while values below zero indicate that colonies reached the food reward faster before the time interval. As intervals become large, food-discovery time returns to the basic initial levels (around zero), which takes place according to this model after ~16 days.</p

The effect of colony size and maze complexity on the three foraging response variables on the first day and test.

<p>The effect of colony size and maze complexity on the three foraging response variables on the first day and test.</p

The effect of day (before and after the time interval) and the time interval between days on the three foraging response variables.

<p>N = sample size (number of colonies).</p