Intraspecific genetic variation of a Fagus sylvatica population in a temperate forest derived from airborne imaging spectroscopy time series

1. The growing pace of environmental change has increased the need for large‐scale monitoring of biodiversity. Declining intraspecific genetic variation is likely a critical factor in biodiversity loss, but is especially difficult to monitor: assessments of genetic variation are commonly based on measuring allele pools, which requires sampling of individuals and extensive sample processing, limiting spatial coverage. Alternatively, imaging spectroscopy data from remote platforms may hold the potential to reveal genetic structure of populations. In this study, we investigated how differences detected in an airborne imaging spectroscopy time series correspond to genetic variation within a population of Fagus sylvatica under natural conditions.
2. We used multi‐annual APEX (Airborne Prism Experiment) imaging spectrometer data from a temperate forest located in the Swiss midlands (Laegern, 47°28'N, 8°21'E), along with microsatellite data from F. sylvatica individuals collected at the site. We identified variation in foliar reflectance independent of annual and seasonal changes which we hypothesize is more likely to correspond to stable genetic differences. We established a direct connection between the spectroscopy and genetics data by using partial least squares (PLS) regression to predict the probability of belonging to a genetic cluster from spectral data.
3. We achieved the best genetic structure prediction by using derivatives of reflectance and a subset of wavebands rather than full‐analyzed spectra. Our model indicates that spectral regions related to leaf water content, phenols, pigments, and wax composition contribute most to the ability of this approach to predict genetic structure of F. sylvatica population in natural conditions.
4. This study advances the use of airborne imaging spectroscopy to assess tree genetic diversity at canopy level under natural conditions, which could overcome current spatiotemporal limitations on monitoring, understanding, and preventing genetic biodiversity loss imposed by requirements for extensive in situ sampling.

     

Calcium signaling during the early meroblastic cleavages of zebrafish and medaka embryos

The regulation of cytokinesis in"gianf' embryonic cells(i.e.,> 500 μm in diameter)presents exacting challenges that include long-range signaling with respect to time and space; the transport and assembly,followed by disassembly,of an extensive contractile apparatus; and the remodeling and addition of new surface membrane to the resulting daughter cells.     

Aggregative oviposition behaviour of Helicoverpa spp. (Lepidoptera: Noctuidae) in contaminated chickpea crops

Abstract Aggregative egg distribution by Helicoverpa spp. within experimental field plots of chickpea containing various contaminant plant species was documented at different stages of plant growth. More eggs were laid on contaminant faba and wheat plants than on the surrounding chickpea. The level of egg aggregation on faba and wheat plants increased with general crop growth, becoming evident before a significant disparity in growth rates between these species and the surrounding chickpea became apparent. In chickpea plots contaminated with canola, aggregative oviposition activity on the contaminant plants was observed in the early seedling stage whilst a clear height differential between the two species was evident. Total Helicoverpa egg density on contaminant plants was not correlated with height above chickpea for any of the contaminant species. It is proposed that the aggregative oviposition behaviour of Helicoverpa spp. in contaminated chickpea results from differential apparency of the contaminant plants to ovipositing moths. Differential apparency may result from several factors including growth rate and morphological differences between chickpea and the contaminants. Physiological changes in chickpea, including growth stage-related changes in acid production by the foliage, may also contribute to the greater apparency of contaminant plants in chickpea plots. The implications of differential host plant apparency for insect pest management are discussed.     

The current status of NMR imaging

A brief account is given of the current status of nuclear-magnetic-resonance (NMR) imaging for medical purposes. The procedures in present use for two- and three-dimensional NMR imaging are outlined and examples given. The quality of images approaches that of computerized tomography X-ray scans and demonstrates superior tissue discrimination and pathological discrimination. Guidelines for safe operation are discussed. Clinical trials of commercial NMR scanners at an advanced stage.     

Decreased Laminin Expression by Human Lung Epithelial Cells and Fibroblasts Cultured in Acellular Lung Scaffolds from Aged Mice

The lung changes functionally and structurally with aging. However, age-related effects on the extracellular matrix (ECM) and corresponding effects on lung cell behavior are not well understood. We hypothesized that ECM from aged animals would induce aging-related phenotypic changes in healthy inoculated cells. Decellularized whole organ scaffolds provide a powerful model for examining how ECM cues affect cell phenotype. The effects of age on ECM composition in both native and decellularized mouse lungs were assessed as was the effect of young vs old acellular ECM on human bronchial epithelial cells (hBECs) and lung fibroblasts (hLFs). Native aged (1 year) lungs demonstrated decreased expression of laminins α3 and α4, elastin and fibronectin, and elevated collagen, compared to young (3 week) lungs. Proteomic analyses of decellularized ECM demonstrated similar findings, and decellularized aged lung ECM contained less diversity in structural proteins compared to young ECM. When seeded in old ECM, hBECs and hLFs demonstrated lower gene expression of laminins α3 and α4, respectively, as compared to young ECM, paralleling the laminin deficiency of aged ECM. ECM changes appear to be important factors in potentiating aging-related phenotypes and may provide clues to mechanisms that allow for aging-related lung diseases.     

Distribution and Numbers of Pygmies in Central African Forests

Pygmy populations occupy a vast territory extending west-to-east along the central African belt from the Congo Basin to Lake Victoria. However, their numbers and actual distribution is not known precisely. Here, we undertake this task by using locational data and population sizes for an unprecedented number of known Pygmy camps and settlements (n = 654) in five of the nine countries where currently distributed. With these data we develop spatial distribution models based on the favourability function, which distinguish areas with favourable environmental conditions from those less suitable for Pygmy presence. Highly favourable areas were significantly explained by presence of tropical forests, and by lower human pressure variables. For documented Pygmy settlements, we use the relationship between observed population sizes and predicted favourability values to estimate the total Pygmy population throughout Central Africa. We estimate that around 920,000 Pygmies (over 60% in DRC) is possible within favourable forest areas in Central Africa. We argue that fragmentation of the existing Pygmy populations, alongside pressure from extractive industries and sometimes conflict with conservation areas, endanger their future. There is an urgent need to inform policies that can mitigate against future external threats to these indigenous peoples’ culture and lifestyles.