Fires can benefit plants by disrupting antagonistic interactions

Fire has a key role in the ecology and evolution of many ecosystems, yet its effects on plant–insect interactions are poorly understood. Because interacting species are likely to respond to fire differently, disruptions of the interactions are expected. We hypothesized that plants that regenerate after fire can benefit through the disruption of their antagonistic interactions. We expected stronger effects on interactions with specialist predators than with generalists. We studied two interactions between two Mediterranean plants (Ulex parviflorus, Asphodelus ramosus) and their specialist seed predators after large wildfires. In A. ramosus we also studied the generalist herbivores. We sampled the interactions in burned and adjacent unburned areas during 2 years by estimating seed predation, number of herbivores and fruit set. To assess the effect of the distance to unburned vegetation we sampled plots at two distance classes from the fire perimeter. Even 3 years after the fires, Ulex plants experienced lower seed damage by specialists in burned sites. The presence of herbivores on Asphodelus decreased in burned locations, and the variability in their presence was significantly related to fruit set. Generalist herbivores were unaffected. We show that plants can benefit from fire through the disruption of their antagonistic interactions with specialist seed predators for at least a few years. In environments with a long fire history, this effect might be one additional mechanism underlying the success of fire-adapted plants

Vascular Endothelial Growth Factor (VEGF) and Platelet (PF-4) Factor 4 Inputs Modulate Human Microvascular Endothelial Signaling in a Three-Dimensional Matrix Migration Context

The process of angiogenesis is under complex regulation in adult organisms, particularly as it often occurs in an inflammatory post-wound environment. As such, there are many impacting factors that will regulate the generation of new blood vessels which include not only pro-angiogenic growth factors such as vascular endothelial growth factor, but also angiostatic factors. During initial postwound hemostasis, a large initial bolus of platelet factor 4 is released into localized areas of damage before progression of wound healing toward tissue homeostasis. Because of its early presence and high concentration, the angiostatic chemokine platelet factor 4, which can induce endothelial anoikis, can strongly affect angiogenesis. In our work, we explored signaling crosstalk interactions between vascular endothelial growth factor and platelet factor 4 using phosphotyrosine-enriched mass spectrometry methods on human dermal microvascular endothelial cells cultured under conditions facilitating migratory sprouting into collagen gel matrices. We developed new methods to enable mass spectrometry-based phosphorylation analysis of primary cells cultured on collagen gels, and quantified signaling pathways over the first 48 h of treatment with vascular endothelial growth factor in the presence or absence of platelet factor 4. By observing early and late signaling dynamics in tandem with correlation network modeling, we found that platelet factor 4 has significant crosstalk with vascular endothelial growth factor by modulating cell migration and polarization pathways, centered around P38α MAPK, Src family kinases Fyn and Lyn, along with FAK. Interestingly, we found EphA2 correlational topology to strongly involve key migration-related signaling nodes after introduction of platelet factor 4, indicating an influence of the angiostatic factor on this ambiguous but generally angiogenic signal in this complex environment.National Science Foundation (U.S.) (NSF EFRI grant 735997)National Institutes of Health (U.S.) (NIH Cell Migration Consortium grant GM06346)National Institutes of Health (U.S.) (NIH Cell Decision Processes Center grant GM68762)National Institutes of Health (U.S.) (NIH grant GM69668)National Institutes of Health (U.S.) (NIH grant GM81336

The Effects of Sex and Strain on <i>Pneumocystis murina</i> Fungal Burdens in Mice

Many preclinical studies of infectious diseases have neglected experimental designs that evaluate potential differences related to sex with a concomitant over-reliance on male model systems. Hence, the NIH implemented a monitoring system for sex inclusion in preclinical studies. Methods: Per this mandate, we examined the lung burdens of Pneumocystis murina infection in three mouse strains in both male and female animals at early, mid, and late time points. Results: Females in each strain had higher infection burdens compared to males at the later time points. Conclusion: Females should be included in experimental models studying Pneumocystis spp

Grazing exclosure increases fruit and seed production but reduces seed viability in Myrtus communis

Plants have compensating mechanisms to alleviate the loss of vegetative and reproductive tissues by herbivores. In this study, we evaluated how reproductive traits (size and production of fruit and seed, as well as germination and viability of seeds) of Myrtus communis (myrtle) were affected by goat grazing exclosure of forest understory in the Doñana Natural Park. One hundred and fifty myrtles were selected in three sites with similar environmental characteristics, although with a different length of grazing exclusion: (1) exclosure for 2 years (GE2); (2) exclosure for 3 years (GE3); and (3) long ago grazed plots (GE15): non-accessible to goat for at least 15 years. Fruit production, fruit and seed morphology and seed viability and germination were evaluated. Length of exclosure to goats increased fruit production, mass and volume of the fruits and seed, and endocarp mass. However, seed viability was higher in more recently grazed plots (70–90%) than in GE15 plots (51%). The final balance of viable/germinable seeds produced by an average sized myrtle in each treatment showed that the recently grazed myrtles (GE2) produced nearly five times less seeds (1200) than the myrtles grazed 15 years ago (5500). However, myrtles recovered the ability to produce viable seeds quickly, almost tripling, each year of non-grazing the number of viable/germinable seeds. The results of this study indicated that goat grazing could affect regeneration of myrtle because it reduced reproduction output and the number of viable propagules. Future studies should evaluate other related ecological aspects, such as fruit consumption by potential frugivores and seed dispersal (distance and place of seed deposition)

Plasma Biomarkers of AD Emerging as Essential Tools for Drug Development: An EU/US CTAD Task Force Report

There is an urgent need to develop reliable and sensitive blood-based biomarkers of Alzheimer’s disease (AD) that can be used for screening and to increase the efficiency of clinical trials. The European Union-North American Clinical Trials in Alzheimer’s Disease Task Force (EU/US CTAD Task Force) discussed the current status of blood-based AD biomarker development at its 2018 annual meeting in Barcelona, Spain. Recent improvements in technologies to assess plasma levels of amyloid beta indicate that a single sample of blood could provide an accurate estimate of brain amyloid positivity. Plasma neurofilament light protein appears to provide a good marker of neurodegeneration, although not specific for AD. Plasma tau shows some promising results but weak or no correlation with CSF tau levels, which may reflect rapid clearance of tau in the bloodstream. Blood samples analyzed using -omics and other approaches are also in development and may provide important insight into disease mechanisms as well as biomarker profiles for disease prediction. To advance these technologies, international multidisciplinary, multi-stakeholder collaboration is essential