Transcriptomic responses of Solanum dulcamara to natural and simulated herbivory

Plants are attacked by diverse herbivores and respond with manifold defence responses. To study transcriptional and other early regulation events of these plant responses, herbivory is often simulated to standardize the temporal and spatial dynamics that vary tremendously for natural herbivory. Yet, to what extent such simulations of herbivory are able to elicit the same plant response as real herbivory remains largely undetermined. We examined the transcriptional response of a wild model plant to herbivory by lepidopteran larvae and to a commonly used herbivory simulation by applying the larvae's oral secretions to standardized wounds. We designed a microarray for Solanum dulcamara and showed that the transcriptional responses to real and to simulated herbivory by Spodoptera exigua overlapped moderately by about 40%. Interestingly, certain responses were mimicked better than others; 60% of the genes upregulated but not even a quarter of the genes downregulated by herbivory were similarly affected by application of oral secretions to wounds. While the regulation of genes involved in signalling, defence and water stress was mimicked well by the simulated herbivory, most of the genes related to photosynthesis, carbohydrate- and lipid metabolism were exclusively regulated by real herbivory. Thus, wounding and application of oral secretions decently mimics herbivory-induced defence responses but likely not the reallocation of primary metabolites induced by real herbivory

Development of a conditional liver tumor model by mifepristone-inducible Cre recombination to control oncogenic kras(V12) expression in transgenic zebrafish

Here we report a new transgenic expression system by combination of liver-specific expression, mifepristone induction and Cre-loxP recombination to conditionally control the expression of oncogenic kras[superscript]V12. This transgenic system allowed expression of kras[superscript]V12 specifically in the liver by a brief exposure of mifepristone to induce permanent genomic recombination mediated by the Cre-loxP system. We found that liver tumors were generally induced from multiple foci due to incomplete Cre-loxP recombination, thus mimicking naturally occurring human tumors resulting from one or a few mutated cells and clonal proliferation to form nodules. Similar to our earlier studies by both constitutive and inducible expression of the kras[superscript]V12 oncogene, hepatocellular carcinoma (HCC) is the main type of liver tumor induced by kras[superscript]V12 expression. Moreover, mixed tumors with hepatocellular adenoma and hepatoblastoma (HB) were also frequently observed. Molecular analyses also indicated similar increase of phosphorylated ERK1/2 in all types of liver tumors, but nuclear localization of β–catenin, a sign of malignant transformation, was found only in HCC and HB. Taken together, our new transgenic system reported in this study allows transgenic kras[superscript]V12 expression specifically in the zebrafish liver only by a brief exposure of mifepristone to induce permanent genomic recombination mediated by the Cre-loxP system.This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by Nature Publishing Group. The published article can be found at: http://www.nature.com/articles/srep1955

Dos and Don'ts in Mobile Phone Sensing Middleware: Learning from a Large-Scale Experiment

International audienceMobile phone sensing contributes to changing the way we approach science: massive amount of data is being contributed across places and time, and paves the way for advanced analyses of numerous phenomena at an unprecedented scale. Still, despite the extensive research work on enabling resource-efficient mobile phone sensing with a very-large crowd, key challenges remain. One challenge is facing the introduction of a new heterogeneity dimension in the traditional middleware research landscape. The middleware must deal with the heterogeneity of the contributing crowd in addition to the system's technical heterogeneities. In order to tackle these two heterogeneity dimensions together, we have been conducting a large-scale empirical study in cooperation with the city of Paris. Our experiment revolves around the public release of a mobile app for urban pollution monitoring that builds upon a dedicated mobile crowd-sensing middleware. In this paper, we report on the empirical analysis of the resulting mobile phone sensing efficiency from both technical and social perspectives, in face of a large and highly heterogeneous population of participants. We concentrate on the data originating from the 20 most popular phone models of our user base, which represent contributions from over 2,000 users with 23 million observations collected over 10 months. Following our analysis, we introduce a few recommendations to overcome-technical and crowd-heterogeneities in the implementation of mobile phone sensing applications and supporting middleware

Effect of 1-MCP, ethylene absorber and ozone on melon quality during storage

This work was aimed to investigate the effect of 1-methylcyclopropene (1-MCP), ethylene absorber (EA), ozone alone or in combination on melon quality during storage. Ethylene production, respiration rates, acoustic firmness, surface color, chilling injury, and disease severity of melon were determined. 1-MCP treated fruits and non 1-MCP treated fruits were stored with sachets of ethylene absorber containing KMnO4 or ozone at 0.1 ppm/h during 10 days at 5 °C and subsequent 4 days at 20 °C. Melons treated with 1-MCP were firmer than the rest of the samples during storage. In addition, 1-MCP reduced the yellowing of melon rind compared to other treatments. The combination of 1-MCP and EA did not offer any additional effect in comparison with 1-MCP alone. There was no significant difference between fruits stored with ethylene absorber, ozone and control samples. Ozone treatment during cold storage decreased disease severity, however, fruits exposed to ozone had more serious decay throughout storage at 20 °C, probably due to the unclean air in the chamber

Long-wave infrared integrated resonators in the 7.5-9 mu m wavelength range

We present broadband on-chip resonators based on SiGe graded-index waveguides operating in the long-wave infrared spectral range from 7.5 to 9.0 mu m wavelength range. A quality factor up to 10(5) has been measured, while an intrinsic quality factor of 1.13 x 10(5) has been extracted from the measurements. Thermal tuning of the phase in the micro-ring has been used to overcome the limitation of the experimental setup in terms of spectral resolution. These results pave the way toward the development of integrated frequency comb operating in the long-wave infrared range

Das NetzDG in der praktischen Anwendung

What are the practical effects of the Network Enforcement Act, which came into force in 2017 and was controversial from the start? Which compliance structures have the big three social networks Facebook, YouTube and Twitter implemented with regard to the removal of illegal user content? In addition to a presentation and evaluation of previous studies, monitoring reports and NetzDG reports from the social networks, possible criteria for “over-blocking” are identified and subsumed in this third volume of the series. On the occasion of the NetzDG evaluation commissioned by the federal government, the study was carried out additionally and independently of this. It is not based on any commissioning by public or private bodies.Welche Auswirkungen hat das 2017 in Kraft getretene, von Beginn an umstrittene Netzwerkdurchsetzungsgesetz in der praktischen Anwendung? Welche Compliance-Strukturen haben die großen drei Sozialen Netzwerke Facebook, YouTube und Twitter in Bezug auf die Entfernung rechtswidriger Nutzerinhalte umgesetzt? Neben einer Darstellung und Bewertung bisheriger Studien, Monitoring-Berichte und NetzDG-Reports der Sozialen Netzwerke werden im vorliegenden dritten Band der Schriftenreihe auch mögliche Kriterien für ein “Overblocking” eruiert und subsumiert. Die Studie ist aus Anlass der von der Bundesregierung beauftragten NetzDG-Evaluation zusätzlich und unabhängig hiervon durchgeführt worden. Ihr liegt keine Beauftragung durch öffentliche oder private Stellen zugrunde

1 GHz electro-optical silicon-germanium modulator in the 5-9 µm wavelength range

: Spectroscopy in the mid-infrared (mid-IR) wavelength range is a key technique to detect and identify chemical and biological substances. In this context, the development of integrated optics systems paves the way for the realization of compact and cost-effective sensing systems. Among the required devices, an integrated electro-optical modulator (EOM) is a key element for advanced sensing circuits exploiting dual comb spectroscopy. In this paper, we have experimentally demonstrated an integrated EOM operating in a wide wavelength range, i.e. from 5 to 9 µm at radio frequency (RF) as high as 1 GHz. The modulator exploits the variation of free carrier absorption in a Schottky diode embedded in a graded silicon germanium (SiGe) photonic waveguide

Room Temperature‐Integrated Photodetector between 5 μm and 8 μm Wavelength

Mid-infrared (mid-IR) optics has a great importance for a large number of applications in sensing, imaging, or even telecommunication. However, high-speed and room-temperature-integrated photodetector (PD) operating in a wide spectrum of the mid-IR is a critical device that is currently missing for the development of compact and efficient spectroscopic systems exploiting synchronous detection. Herein, a waveguide-integrated PD based on a Schottky diode embedded in a graded silicon germanium waveguide is demonstrated. Photodetection is obtained in a wide spectral range from 5 to 8 μm wavelength, with responsivity reaching up to 0.1 mA W−1. Photodetection performed in pulsed regime with laser pulse width between 50 and 200 ns indicates an operation beyond 20 MHz. Interestingly, the achieved performances indicate that this device is already suitable for on-chip signal monitoring, while further improvement can pave the way toward advanced compact and fully integrated spectroscopic systems operating in long-wave infrared regions