A common pesticide decreases foraging success and survival in honey bees

Nonlethal exposure of honey bees to thiamethoxam (neonicotinoid systemic pesticide) causes high mortality due to homing failure at levels that could put a colony at risk of collapse. Simulated exposure events on free-ranging foragers labeled with a radio-frequency identification tag suggest that homing is impaired by thiamethoxam intoxication. These experiments offer new insights into the consequences of common neonicotinoid pesticides used worldwide.     

Anatomical and biochemical trait network underlying genetic variations in tomato fruit texture

Firmness is an indicator of fruit freshness and a main component of tomato (Solanum lycopersicum) fruit texture. In this work, the genetic variability in fruit firmness and stiffness was analyzed in pre- and postharvest periods and underlying anatomical and biochemical traits were identified. Three tomato contrasted parental lines and six derived quantitative trait loci (QTL)-NILs harboring texture QTL on chromosome 4 (QTL4) and 9 (QTL9) were analyzed; the seasonal variability was assessed on two distant trusses. Firmness and stiffness were measured by compression and puncture tests at harvest and after 7-day storage at 20 °C. QTL4 poorly influenced the textural variables, on the contrary to QTL9 which increased firmness measured by puncture test and had similar effects in the two genetic backgrounds. According to this test, firmness increased along the season, but ranks among genotypes and QTL effects were hardly affected. Only some of the QTL effects were still significant after storage and firmness losses were not predicted by firmness at harvest. Fruit firmness and stiffness measured by puncture tests correlated with both morphological (locular number, R = −0.89), histological (cell size, R < −0.80) and biochemical (dry matter (R > 0.82) and soluble sugar content (R < −0.74)) fruit traits. In contrast, compression test values hardly correlated with any of the measured traits. This work provided an original comprehensive approach to analyse fleshy fruit firmness and paves the way for a future predictive model.     

Solanum incanum and S. heteracanthum as sources of biologically active steroid glycosides: confirmation of their synonymy

A new spirostanol saponin (1), along with four known saponins, dioscin (2), protodioscin (3), methyl-protodioscin (4), and indioside D (5), and one known steroid glycoalkaloid solamargine (6) were isolated from the two synonymous species, Solanum incanum and S. heteracanthum. The structure of the new saponin was established as (23S,25R)-spirost-5-en-3β,23-diol 3-O-{β-D-xylopyranosyl-(1→2)-O-α-L-rhamnopyranosyl-(1→4)-[O-α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranoside}, by using a combination of 1D and 2D NMR techniques including (1)H, (13)C, COSY, TOCSY, NOESY, HSQC and HMBC experiments and by mass spectrometry. The compounds 1, 3, 4 and 5 were evaluated for cytotoxicity against five cancer cell lines and for antioxidant and cytoprotective activity.     

Comparison of the amounts of volatile compounds in French protected designation of origin virgin olive oils

Headspace solid-phase microextraction (HS-SPME) -gas chromatography using flame ionization detection and multivariate analysis were applied to the study of the specificity of protected designation of origin (PDO) virgin olive oils produced in a southern French region (Alpes-Maritimes) based on their volatile compounds. A total of 35 PDO olive oils from Nice, 6 commercial oils, and 12 other French PDO olive oils were analyzed. Recorded data were subjected to principal component analysis (PCA) and soft independent modeling of class analogy (SIMCA). The method developed here was able to perfectly distinguish different qualities of olive oils. Representative samples from each class obtained by chemometric treatment were analyzed by HS-SPME and GC-MS. PCA and SIMCA of chromatographic data were related to sensory analysis and led to a better understanding of the chemical features and observed sensory effects of olive oils.     

The age of the Sahara desert

In the Sahara region, the age of onset of the desert condition has been uncertain until now. Here we report on the discovery of 7,000,000-year-old eolian dune deposits from the northern Chad Basin. This geological archive is the oldest known evidence for desert occurrence in the Sahara.     

Matrix configuration and patch isolation influences override the species–area relationship for urban butterfly communities

The aim of this paper is to examine the role of urban public parks in maintaining connectivity and butterfly assemblages. Using a regression framework, we first test the relative importance of park size and isolation in predicting abundance and species richness of butterfly assemblages across a set of 24 public parks within a large metropolitan area, Marseille (South-East France). Then, we focus on landscape features that affect diversity patterns of the recorded butterfly communities. In this second part, the urban landscape surrounding each park is described (within a 1 × 1 km window) according to two major components: vegetated areas (habitat patches) and impervious or built areas (matrix patches). Specifically, we aim to test whether the incorporation of this built component (matrix) in the landscape analysis provides new insights into the understanding of ecological connectivity in the urban environment. We found a significant effect of both matrix configuration (shape complexity of the built patches) and distance from regional species pool (park isolation) on diversity of butterflies that overrides park size in their contribution to variation in species richness. This result suggests that many previous studies of interactions between biodiversity and urban landscape have overlooked the influence of the built elements.     

Combining farmers’ decision rules and landscape stochastic regularities for landscape modelling

Landscape spatial organization (LSO) strongly impacts many environmental issues. Modelling agricultural landscapes and describing meaningful landscape patterns are thus regarded as key-issues for designing sustainable landscapes. Agricultural landscapes are mostly designed by farmers. Their decisions dealing with crop choices and crop allocation to land can be generic and result in landscape regularities, which determine LSO. This paper comes within the emerging discipline called “landscape agronomy”, aiming at studying the organization of farming practices at the landscape scale. We here aim at articulating the farm and the landscape scales for landscape modelling. To do so, we develop an original approach consisting in the combination of two methods used separately so far: the identification of explicit farmer decision rules through on-farm surveys methods and the identification of landscape stochastic regularities through data-mining. We applied this approach to the Niort plain landscape in France. Results show that generic farmer decision rules dealing with sunflower or maize area and location within landscapes are consistent with spatiotemporal regularities identified at the landscape scale. It results in a segmentation of the landscape, based on both its spatial and temporal organization and partly explained by generic farmer decision rules. This consistency between results points out that the two modelling methods aid one another for land-use modelling at landscape scale and for understanding the driving forces of its spatial organization. Despite some remaining challenges, our study in landscape agronomy accounts for both spatial and temporal dimensions of crop allocation: it allows the drawing of new spatial patterns coherent with land-use dynamics at the landscape scale, which improves the links to the scale of ecological processes and therefore contributes to landscape ecology.     

Comparison of static headspace, headspace solid phase microextraction, headspace sorptive extraction, and direct thermal desorption techniques on chemical composition of French olive oils

Static headspace (SHS), headspace solid phase microextraction (HS-SPME), headspace sorptive extraction (HSSE), and direct thermal desorption (DTD) were applied to the analysis of four French virgin olive oils from Corsica. More than 60 compounds were isolated and characterized by GC-RI and GC-MS. SHS was not suited to the characterization of olive oil volatile compounds because of low sensitivity. The SPME and HSSE techniques were successfully applied to olive oil headspace analysis. Both methods allow the characterization of volatile compounds (mainly C(6) aldehydes and alcohols), which contribute significantly to the "green" flavor note of virgin olive oils. The PDMS stir bar showed a higher concentration capacity than a DVB/CAR/PDMS SPME fiber due to the higher volume of polymeric coating. DTD was a very good tool for extracting volatile and especially semivolatile compounds, such as sesquiterpenes, but requires a significant investment like that for HSSE. Finally, SPME may be a more appropriate technique for routine quality control due to its operational simplicity, repeatability, and low cost.     

Use of differential scanning calorimetry (DSC) as a new technique for detection of adulteration in honeys. 1. Study of adulteration effect on honey thermal behavior.

Differential scanning calorimetry (DSC) was used to study the thermal behavior of authentic honeys (Lavandula, Robinia, and Fir honeys) and industrial sugar syrups. Thermal or thermochemical parameters such as the glass transition temperature (Tg), enthalpies of fusion (DeltaH(fus)), and heat capacity variation (DeltaC(p)) were measured. The syrups and honeys showed significant differences in thermal phenomena, as well as in their amplitude and position on the temperature scale. Results showed good reproducibility of the method for all samples studied. The effect of adulteration of honey with different amounts of syrup (5, 10, 20, 40, and 60%) was investigated. A linear relationship was found between the percentage of added syrup and the glass transition temperature. A similar relationship was obtained from the enthalpy of fusion results in the temperature range of 40-90 degrees C. Under applied conditions, the effects of adulteration of honeys by industrial syrups appeared to be detectable from a level as low as 5%.     

Origin of the color of Cv. rhapsody in blue rose and some other so-called "blue" roses

Flowers of the rose cultivar Rhapsody in Blue display unusual colors, changing as they age, from a vivid red-purple to a lighter and duller purple, which are based on tonalities corresponding to hue angles between 340 and 320 degrees in the CIELAB scale. Unexpectedly, the chemical basis of these colors is among the simplest, featuring cyanin (cyanidin 3,5-di-O-glucoside), the most frequent anthocyanin in flowers, as the sole pigment and quercetin kaempferol glycosides as copigments at a relatively low copigment/pigment ratio (about 3/1), which usually produces magenta or red shades in roses. This color shift to bluer shades is coupled with the progressive accumulation of cyanin into vacuolar anthocyanic inclusions (AVIs), the occurrence of which increases as the petals grow older. In addition to the normal lambda(max) of cyanin at approximately 545 nm, the transmission spectra of live petals and of epidermal cells exhibit a second lambda(max) in the 620-625 nm range, the relative importance increasing with the presence of AVIs. In petals of fully opened flowers, the only pigmented structures in the vacuoles of epidermal cells are AVIs; their intense and massive absorption in the 520-640 nm area produces a much darker and bluer color than measured for the vacuolar solution present at the very first opening stage. Cyanin is probably "trapped" into AVIs at higher concentrations than would be possible in a vacuolar solution and in quinonoidal form, appearing purple-blue because of additional absorption in the 580-630 nm area. Quite similar pigmentation features were found in very ancient rose cultivars (cv. L'Evêque or Bleu Magenta), also displaying this type of so-called "blue" color.