Natural variation in stomata size contributes to the local adaptation of water-use efficiency in Arabidopsis thaliana

Stomata control gas exchanges between the plant and the atmosphere. How natural variation in stomata size and density contributes to resolve trade-offs between carbon uptake and water loss in response to local climatic variation is not yet understood. We developed an automated confocal microscopy approach to characterize natural genetic variation in stomatal patterning in 330 fully sequenced Arabidopsis thaliana accessions collected throughout the European range of the species. We compared this to variation in water-use efficiency, measured as carbon isotope discrimination (C-13). We detect substantial genetic variation for stomata size and density segregating within Arabidopsis thaliana. A positive correlation between stomata size and C-13 further suggests that this variation has consequences on water-use efficiency. Genome wide association analyses indicate a complex genetic architecture underlying not only variation in stomatal patterning but also to its covariation with carbon uptake parameters. Yet, we report two novel QTL affecting C-13 independently of stomatal patterning. This suggests that, in A. thaliana, both morphological and physiological variants contribute to genetic variance in water-use efficiency. Patterns of regional differentiation and covariation with climatic parameters indicate that natural selection has contributed to shape some of this variation, especially in Southern Sweden, where water availability is more limited in spring relative to summer. These conditions are expected to favour the evolution of drought avoidance mechanisms over drought escape strategies

The just meaningful difference in speech-to-noise ratio

The speech-to-noise ratio (SNR) in an environment plays a vital role in speech communication for both normal-hearing (NH) and hearing-impaired (HI) listeners. While hearing-assistance devices attempt to deliver as favorable an SNR as possible, there may be discrepancies between noticeable and meaningful improvements in SNR. Furthermore, it is not clear how much of an SNR improvement is necessary to induce intervention-seeking behavior. Here we report on a series of experiments examining the just-meaningful difference (JMD) in SNR. All experiments used sentences in same-spectrum noise, with two intervals on each trial mimicking examples of pre- and post-benefit situations. Different groups of NH and HI adults were asked (a) to rate how much better or worse the change in SNR was in a number of paired examples, (b) if they would swap the worse for the better SNR (e.g., their current device for another) or (c) if they would be willing to go to the clinic for the given increase in SNR. The mean SNR JMD based on better/worse ratings (one arbitrary unit) was similar to the just-noticeable difference, approximately 3 dB. However, the mean SNR JMD for the more clinically relevant tasks -- willingness (at least 50% of the time) to swap devices or attend the clinic for a change in SNR -- was 6-8 dB regardless of hearing ability. This SNR JMD of the order of 6 dB provides a new benchmark, indicating the SNR improvement necessary to immediately motivate participants to seek intervention

Survey of highly non-Keplerian orbits with low-thrust propulsion

Celestial mechanics has traditionally been concerned with orbital motion under the action of a conservative gravitational potential. In particular, the inverse square gravitational force due to the potential of a uniform, spherical mass leads to a family of conic section orbits, as determined by Isaac Newton, who showed that Kepler‟s laws were derivable from his theory of gravitation. While orbital motion under the action of a conservative gravitational potential leads to an array of problems with often complex and interesting solutions, the addition of non-conservative forces offers new avenues of investigation. In particular, non-conservative forces lead to a rich diversity of problems associated with the existence, stability and control of families of highly non-Keplerian orbits generated by a gravitational potential and a non-conservative force. Highly non-Keplerian orbits can potentially have a broad range of practical applications across a number of different disciplines. This review aims to summarize the combined wealth of literature concerned with the dynamics, stability and control of highly non-Keplerian orbits for various low thrust propulsion devices, and to demonstrate some of these potential applications

Erste Erfahrungen mit dem NBI-System an der HNO-Klinik Erlangen

Einleitung: Das narrow band imaging (NBI) ist ein neues innovatives klinisches bildgebendes Verfahren, welches schmalbandiges Licht mit zwei Wellenlängen (415nm und 540nm) einsetzt. Es wird von Gefäßen absorbiert und von Schleimhaut reflektiert. Der dadurch entstandene Gefäßkontrast ermöglicht eine dezidierte Beurteilung pathologischer Gefäßanomalien, die sich bei malignen Läsionen charakteristisch zeigen. Methode: Ziel der vorliegenden Untersuchung war die routinetaugliche Evaluation von Schleimhautveränderungen, welche unter NBI besser zu erkennen sind als unter Weißlicht. Bei 10 Patienten wurde das NBI-System sowohl mittels flexibler Optik zur gröberen Orientierung als auch eine Kombinationsanwendung mit einem Kontaktendoskop zur genaueren Gefäßdarstellung durchgeführt und mit regulärer Weißlichtendoskopie verglichen.Ergebnisse: Im Vergleich zur Weißlichtendoskopie konnten bei malignen Läsionen Gefäßanomalien mittels NBI besser kontrastiert werden. Durch die zusätzliche Anwendung eines Kontaktendoskopes wurde die Darstellung von Gefäßanomalien (z.B. Loops, Gefäßabbrüche) sehr deutlich. Rückschlüsse auf die Dignität von Gewebsveränderungen lassen sich so vermuten.Schlussfolgerung: Das NBI schafft eine Möglichkeit die klinische Aussagekraft der Endoskopie zu erhöhen und dabei die Biopsieentnahme zu optimieren bzw. die Biopsie-Notwendigkeit besser zu beurteilen. Weitere Studien mit höherer Patientenanzahl und histologischer Korrelation sind nötig um die Ergebnisse zu validieren.Der Erstautor gibt keinen Interessenkonflikt an

ОЦЕНКА ВОЗМОЖНОСТИ ПРОМЫШЛЕННОГО ПРОИЗВОДСТВА РЕДКОЗЕМЕЛЬНЫХ ЭЛЕМЕНТОВ ДЛЯ ПОЛУЧЕНИЯ ВЫСОКОЭНЕРГЕТИЧЕСКИХ МАГНИТОВ В УКРАИНЕ

In this article, the possibilities and limitations of proximity lithography with extreme ultraviolet (EUV) radiation are explored theoretically and experimentally. Utilizing partially coherent EUV radiation with a wavelength of 10.88 nm from a Xe/Ar discharge plasma EUV source, proximity patterning of various nanoantenna arrays has been performed. The experimental results are compared with the results of numerical scalar diffraction simulations, and it is shown that proximity printing in the Fresnel diffraction mode can enable production of high-resolution features even with lower resolution masks, successfully demonstrating sub-30 nm edge resolution in the resist. The potential of the method is explored by simulation of the patterning through circular and triangular apertures as well as through bowtie antenna patterns, with the results suggesting that precise control of the proximity gap and the exposure dose together with simulation-supported mask design optimizations may allow for a wide variety of high-resolution structures to be printed through relatively simple transmission masks. The method is especially suited for high-performance manufacturing of submicrometer sized nanophotonic arrays