Sex-Differential Herbivory in Androdioecious Mercurialis annua

Males of plants with separate sexes are often more prone to attack by herbivores than females. A common explanation for this pattern is that individuals with a greater male function suffer more from herbivory because they grow more quickly, drawing more heavily on resources for growth that might otherwise be allocated to defence. Here, we test this ‘faster-sex’ hypothesis in a species in which males in fact grow more slowly than hermaphrodites, the wind-pollinated annual herb Mercurialis annua. We expected greater herbivory in the faster-growing hermaphrodites. In contrast, we found that males, the slower sex, were significantly more heavily eaten by snails than hermaphrodites. Our results thus reject the faster-sex hypothesis and point to the importance of a trade-off between defence and reproduction rather than growth

Belle II Technical Design Report

The Belle detector at the KEKB electron-positron collider has collected almost 1 billion Y(4S) events in its decade of operation. Super-KEKB, an upgrade of KEKB is under construction, to increase the luminosity by two orders of magnitude during a three-year shutdown, with an ultimate goal of 8E35 /cm^2 /s luminosity. To exploit the increased luminosity, an upgrade of the Belle detector has been proposed. A new international collaboration Belle-II, is being formed. The Technical Design Report presents physics motivation, basic methods of the accelerator upgrade, as well as key improvements of the detector.Comment: Edited by: Z. Dole\v{z}al and S. Un

Specialized Learning in Antlions (Neuroptera: Myrmeleontidae), Pit-Digging Predators, Shortens Vulnerable Larval Stage

Unique in the insect world for their extremely sedentary predatory behavior, pit-dwelling larval antlions dig pits, and then sit at the bottom and wait, sometimes for months, for prey to fall inside. This sedentary predation strategy, combined with their seemingly innate ability to detect approaching prey, make antlions unlikely candidates for learning. That is, although scientists have demonstrated that many species of insects possess the capacity to learn, each of these species, which together represent multiple families from every major insect order, utilizes this ability as a means of navigating the environment, using learned cues to guide an active search for food and hosts, or to avoid noxious events. Nonetheless, we demonstrate not only that sedentary antlions can learn, but also, more importantly, that learning provides an important fitness benefit, namely decreasing the time to pupate, a benefit not yet demonstrated in any other species. Compared to a control group in which an environmental cue was presented randomly vis-à-vis daily prey arrival, antlions given the opportunity to associate the cue with prey were able to make more efficient use of prey and pupate significantly sooner, thus shortening their long, highly vulnerable larval stage. Whereas “median survival time,” the point at which half of the animals in each group had pupated, was 46 days for antlions receiving the Learning treatment, that point never was reached in antlions receiving the Random treatment, even by the end of the experiment on Day 70. In addition, we demonstrate a novel manifestation of antlions' learned response to cues predicting prey arrival, behavior that does not match the typical “learning curve” but which is well-adapted to their sedentary predation strategy. Finally, we suggest that what has long appeared to be instinctive predatory behavior is likely to be highly modified and shaped by learning

A biology-based approach for quantitative structure-activity relationships (QSARs) in ecotoxicity.

Quantitative structure-activity relationships (QSARs) for ecotoxicity can be used to fill data gaps and limit toxicity testing on animals. QSAR development may additionally reveal mechanistic information based on observed patterns in the data. However, the use of descriptive summary statistics for toxicity, such as the 4-day LC50 for fish, introduces bias and ignores valuable kinetic information in the data. Biology-based methods use all of the toxicity data in time to derive time-independent and unbiased parameter estimates. Such an approach offers whole new opportunities for mechanism-based QSAR development. In this paper, we apply the hazard model from DEBtox to analyse survival data for fathead minnows (Pimephales promelas). Different modes of action resulted in different patterns in the parameter estimates, and therefore, the toxicity data by themselves reveal insight into the actual mechanism of toxic action

Tree influence exacerbates the El Niño effects over soil CO<inf>2</inf> emissions and its microclimatic controls

Dryland ecosystems are considered the largest global carbon sink. However, extreme climate phenomena like the El Niño events (EN) may change soil respiration (Rs) the CO2 emitted from soils resulting from biological activity and the largest outgoing flux of carbon from terrestrial ecosystems. Our aim was to study the effect of the EN on Rs in the North Peruvian dryland forest, and its interaction with soil temperature and the tree canopy. Our results indicate that Rs during the EN years increased by a factor of 100 compared to normal years, but this effect was exacerbated by the proximity to trees. Only under trees and during the EN event temperature exerted a positive control over daily Rs fluctuations. Our results, indicate how in these dryland forests the expected increase in the EN frequency and intensity could affect soil CO2 emissions, and hence ecosystem carbon budgets, but that this effect would very much depend on tree density and tree spatial distribution. © 2019 Elsevier B.V.Financial support was provided by the Peruvian program CONCYTEC (163-2018-FONDECYT-BM-IADT-SE) granted to Dr. Pablo Salazar. Jorge Curiel Yuste is indebted to the Basque Government through the BERC 2018-2021 program, and by the Spanish Ministry of Science, Innovation and Universities through the BC3 Mar?a de Maeztu excellence accreditation (MDM-2017-0714)

A stromal cell free culture system generates mouse pro-t cells that can reconstitute t-cell compartments in vivo

T-cell lymphopenia following BM transplantation or diseases such as AIDS result in immunodeficiency. Novel approaches to ameliorate this situation are urgently required. Herein, we describe a novel stromal cell free culture system in which Lineage(-)Sca1(+)c-kit(+) BM hematopoietic progenitors very efficiently differentiate into pro-T cells. This culture system consists of plate-bound Delta-like 4 Notch ligand and the cytokines SCF and IL-7. The pro-T cells developing in these cultures express CD25, CD117, and partially CD44; express cytoplasmic CD3 epsilon; and have their TCR locus partially D-J rearranged. They could be expanded for over 3 months and used to reconstitute the T-cell compartments of sublethally irradiated T-cell-deficient CD3 epsilon(-/-) mice or lethally irradiated WT mice. Pro-T cells generated in this system could partially correct the T-cell lymphopenia of pre-T-/- mice. However, reconstituted CD3 epsilon(-/-) mice suffered from a wasting disease that was prevented by co-injection of purified CD4(+) CD25(high) WT Treg cells. In a T-cell-sufficient or T-lymphopenic setting, the development of disease was not observed. Thus, this in vitro culture system represents a powerful tool to generate large numbers of pro-T cells for transplantation and possibly with clinical applications

Comparing quantile residual life functions by confidence bands

In this article we present a nonparametric method for constructing confidence bands for the difference of two quantile residual life (qrl) functions. These bands provide evidence for two random variables ordering with respect to the qrl order. The comparison of qrl functions is of importance, specially in the treatment of cancer when there exists a possibility of benefiting from a new secondary therapy. A qrl function is the quantile of the remaining life of a surviving subject, as it varies with time. We show the applicability of this approach in Medicine and Ecology. A simulation study has been carried out to evaluate and illustrate the performance and the consistency of this new methodology