Eco‐evolutionary dynamics in response to selection on life‐history

Understanding the consequences of environmental change on ecological and evolutionary dynamics is inherently problematic because of the complex interplay between them. Using invertebrates in microcosms, we characterise phenotypic, population and evolutionary dynamics before, during and after exposure to a novel environment and harvesting over 20 generations. We demonstrate an evolved change in life-history traits (the age- and size-at-maturity, and survival to maturity) in response to selection caused by environmental change (wild to laboratory) and to harvesting (juvenile or adult). Life-history evolution, which drives changes in population growth rate and thus population dynamics, includes an increase in age-to-maturity of 76% (from 12.5 to 22 days) in the unharvested populations as they adapt to the new environment. Evolutionary responses to harvesting are outweighed by the response to environmental change (~ 1.4 vs. 4% change in age-at-maturity per generation). The adaptive response to environmental change converts a negative population growth trajectory into a positive one: an example of evolutionary rescue. © 2013 John Wiley & Sons Ltd/CNRS

Mapping interacting QTL for count phenotypes using hierarchical Poisson and binomial models: an application to reproductive traits in mice

We proposed hierarchical Poisson and binomial models for mapping multiple interacting quantitative trait loci (QTL) for count traits in experimental crosses. We applied our methods to two counted reproductive traits, live fetuses (LF) and dead fetuses (DF) at 17 days gestation, in a F2 female mouse population. We treated observed number of corpora lutea (ovulation rate) as the baseline and the total trials in our Poisson and binomial models, respectively. We detected more than 10 QTL for LF and DF, most having epistatic and pleiotropic effects. The epistatic effects were larger, involved more QTL, and explained a larger proportion of phenotypic variance than the main effects. Our analyses revealed a complex network of multiple interacting QTL for the reproductive traits, and increase our understanding of the genetic architecture of reproductive characters. The proposed statistical models and methods provide valuable tools for detecting multiple interacting QTL for complex count phenotypes

Comparing gene panels for non-retinal indications: A systematic review

IMPORTANCE: The options for genetic testing continue to grow for ocular conditions, including optic atrophy, anterior segment dysgenesis, cataracts, corneal dystrophy, nystagmus, and glaucoma. Gene panels can vary in content and coverage, as we and others have evaluated in inherited retinal disease (IRD). OBJECTIVE: To describe gene panel testing options for inherited eye disease phenotypes and their differences. This review is important for making diagnostic decisions. EVIDENCE REVIEW: A licensed, certified genetic counselor (RP) used Concert Genetics and the search terms optic atrophy, corneal dystrophy, cataract, glaucoma, anterior segment dysgenesis, microphthalmia/anophthalmia, and nystagmus to identify available testing options performed by CLIA-certified commercial genetic testing laboratories. Other co-authors were surveyed with respect to genetic panels used for the indications of interest. Ophthalmic panels were then compared using Concert Genetics in addition to their own websites. FINDINGS: Panels from each clinical category were included and summarized. This comparison highlighted the differences and similarities between panels so that clinicians can make informed decisions. CONCLUSIONS: Access to genetic testing is increasing. The diagnostic yield of genetic testing is increasing. Each panel is different, so phenotyping or characterizing clinical characteristics that may help predict a specific genotype, as well as pre-test hypotheses regarding a genotype, should shape the choice of panels

Comparative Analysis of the Frequency and Distribution of Stem and Progenitor Cells in the Adult Mouse Brain

cells (NSCs) and progenitor cells, but it cannot discriminate between these two populations. Given two assays have purported to overcome this shortfall, we performed a comparative analysis of the distribution and frequency of NSCs and progenitor cells detected in 400 m coronal segments along the ventricular neuraxis of the adult mouse brain using the neurosphere assay, the neural colony forming cell assay (N-CFCA), and label-retaining cell (LRC) approach. We observed a large variation in the number of progenitor/stem cells detected in serial sections along the neuraxis, with the number of neurosphereforming cells detected in individual 400 m sections varying from a minimum of eight to a maximum of 891 depending upon the rostral-caudal coordinate assayed. Moreover, the greatest variability occurred in the rostral portion of the lateral ventricles, thereby explaining the large variation in neurosphere frequency previously reported. Whereas the overall number of neurospheres (3730 276) or colonies (4275 124) we detected along the neuraxis did not differ significantly, LRC numbers were significantly reduced (1186 188, 7 month chase) in comparison to both total colonies and neurospheres. Moreover, approximately two orders of magnitude fewer NSC-derived colonies (50 10) were detected using the N-CFCA as compared to LRCs. Given only 5% of the LRCs are cycling (BrdU/Ki-67) or competent to divide (BrdU/Mcm-2), and proliferate upon transfer to culture, it is unclear whether this technique selectively detects endogenous NSCs. Overall, caution should be taken with the interpretation and employment of all these techniques

Vegetation response to invasive Tamarix control in southwestern U.S. rivers: a collaborative study including 416 sites

Most studies assessing vegetation response following control of invasive Tamarix trees along southwestern U.S. rivers have been small in scale (e.g., river reach), or at a regional scale but with poor spatial-temporal replication, and most have not included testing the effects of a now widely used biological control. We monitored plant composition following Tamarix control along hydrologic, soil, and climatic gradients in 244 treated and 172 reference sites across six U.S. states. This represents the largest comprehensive assessment to date on the vegetation response to the four most common Tamarix control treatments. Biocontrol by a defoliating beetle (treatment 1) reduced the abundance of Tamarix less than active removal by mechanically using hand and chain-saws (2), heavy machinery (3) or burning (4). Tamarix abundance also decreased with lower temperatures, higher precipitation, and follow-up treatments for Tamarix resprouting. Native cover generally increased over time in active Tamarix removal sites, however, the increases observed were small and was not consistently increased by active revegetation. Overall, native cover was correlated to permanent stream flow, lower grazing pressure, lower soil salinity and temperatures, and higher precipitation. Species diversity also increased where Tamarix was removed. However, Tamarix treatments, especially those generating the highest disturbance (burning and heavy machinery), also often promoted secondary invasions of exotic forbs. The abundance of hydrophytic species was much lower in treated than in reference sites, suggesting that management of southwestern U.S. rivers has focused too much on weed control, overlooking restoration of fluvial processes that provide habitat for hydrophytic and floodplain vegetation. These results can help inform future management of Tamarix-infested rivers to restore hydrogeomorphic processes, increase native biodiversity and reduce abundance of noxious species

A Broadband Study of the Emission from the Composite Supernova Remnant MSH 11-62

MSH 11-62 (G291.1-0.9) is a composite supernova remnant for which radio and X-ray observations have identified the remnant shell as well as its central pulsar wind nebula. The observations suggest a relatively young system expanding into a low density region. Here we present a study of MSH 11-62 using observations with the Chandra, XMM-Newton, and Fermi observatories, along with radio observations from the Australia Telescope Compact Array (ATCA). We identify a compact X-ray source that appears to be the putative pulsar that powers the nebula, and show that the X-ray spectrum of the nebula bears the signature of synchrotron losses as particles diffuse into the outer nebula. Using data from the Fermi LAT, we identify gamma-ray emission originating from MSH 11-62. With density constraints from the new X-ray measurements of the remnant, we model the evolution of the composite system in order to constrain the properties of the underlying pulsar and the origin of the gamma-ray emission.Comment: 12 Pages, 12 figures. Accepted for publication in the Astrophysical Journa

FRP-to-masonry bond durability assessment with infrared thermography method

The bond behavior between FRP composites and masonry substrate plays an important role in the performance of externally bonded reinforced masonry structures. Therefore, monitoring the bond quality during the application and subsequent service life of a structure is of crucial importance for execution control and structural health monitoring. The bond quality can change during the service life of the structure due to environmental conditions. Local detachments may occur at the FRP/substrate interface, affecting the bond performance to a large extent. Therefore, the use of expedite and efficient non-destructive techniques for assessment of the bond quality and monitoring FRP delamination is of much interest. Active infrared thermography (IR) technique was used in this study for assessing the bond quality in environmentally degraded FRP-strengthened masonry elements. The applicability and accuracy of the adopted method was initially validated by localization and size quantification of artificially embedded defects in FRP-strengthened brick specimens. Then, the method was used for investigating the appearance and progression of FRP delaminations due to environmental conditions. GFRP-strengthened brick specimens were exposed to accelerated hygrothermal ageing tests and inspected periodically with the IR camera. The results showed environmental exposure may produce large progressive FRP delaminations.Fundação para a Ciência e Tecnologi