Self-incompatibility system of Oenothera organensis for the detection of genetic effects at low radiation doses.

The self-incompatibility system of Oenothera organensis is used to analyze the frequency of S locus mutations induced by low doses (2.5-20 rad) of fast neutrons and x-rays. Th principles and methods of the screening system for detection of low dose effects have been presented. The results show that low doses induced significantly higher frequencies of seeds and seedlings than those produced spontaneously. The analyses of part of the progenies derived from the control and treated series suggested that they were due to revertible mutations. A modified in vitro method of culturing pollinated cut styles has been developed for rapid screening of compatible pollen tubes

Coherent vibrations of submicron spherical gold shells in a photonic crystal

Coherent acoustic radial oscillations of thin spherical gold shells of submicron diameter excited by an ultrashort optical pulse are observed in the form of pronounced modulations of the transient reflectivity on a subnanosecond time scale. Strong acousto-optical coupling in a photonic crystal enhances the modulation of the transient reflectivity up to 4%. The frequency of these oscillations is demonstrated to be in good agreement with Lamb theory of free gold shells.Comment: Error in Eqs.2 and 3 corrected; Tabl. I corrected; Fig.1 revised; a model that explains the dependence of the oscillation amplitude of the transient reflectivity with wavelength adde

A highly efficient titanium-based olefin polymerisation catalyst with a monoanionic iminoimidazolidide pi-donor ancillary ligand

The titanium complex Cp[1,3-(2',6' Me2C6H3) (2)(CH2N)(2)C=N] Ti(CH2Ph)(2), with a monoanionic eta(1)-iminoimidazolidide ancillary ligand, is shown to be a highly efficient catalyst for olefin polymerisation when activated with the Lewis acid B(C6F5)(3)

Розвиток історико-краєзнавчої бібліографії в Криму (20–30-ті роки ХХ століття)

Викладені передумови розвитку краєзнавчої бібліографії в Кримській АРСР, виділені її відмінні риси. Схарактеризована діяльність видатного історика, ученого-краєзнавця А. І. Маркевича. Висвітлений внесок у розвиток історико-краєзнавчої бібліографії Криму бібліографів В. В. Симоновського, Д. М. Єгорова, Д. С. Спиридонова, Ф. П. Максименка та ін.Изложены предпосылки развития краеведческой библиографии в Крымской АССР, выделены ее отличительные черты. Рассмотрена деятельность выдающегося историка, ученого-краеведа А. И. Маркевича. Дан анализ его фундаментального труда “TAURICA”, который является одним из ключевых историко-краеведческих пособий, созданных в период существования Крымской АССР.The prerequisites of the development of regional bibliography in the Crimean ASSR are presented, its distinguishing features are allocated. The activity of the outstanding historian, scientist- student of local lore A. I. Markevich is examined. There is the analysis of its fundamental work “TAURICA”, which is one of the key historic- regional textbook, created in the time of Crimean ASSR. There is the characteristic of indicators by V. V. Simonovskiy — “bibliography of krymovedeniya”. The contribution to development of the historic- regional bibliography of Crimea the bibliographers D. N. Yegorov, D. S. Spiridonov, F. F. Maksimenko and others is illuminated

Long-range potential fluctuations and 1/f noise in hydrogenated amorphous silicon

We present a microscopic theory of the low-frequency voltage noise (known as "1/f" noise) in micrometer-thick films of hydrogenated amorphous silicon. This theory traces the noise back to the long-range fluctuations of the Coulomb potential produced by deep defects, thereby predicting the absolute noise intensity as a function of the distribution of defect activation energies. The predictions of this theory are in very good agreement with our own experiments in terms of both the absolute intensity and the temperature dependence of the noise spectra.Comment: 8 pages, 3 figures, several new parts and one new figure are added, but no conceptual revision

Correlated terahertz acoustic and electromagnetic emission in dynamically screened InGaN/GaN quantum wells

We investigate acoustic and electromagnetic emission from optically excited strained piezoelectric In0.2Ga0.8N/GaN multiple quantum wells (MQWs), using optical pump-probe spectroscopy, time-resolved Brillouin scattering, and THz emission spectroscopy. A direct comparison of detected acoustic signals and THz electromagnetic radiation signals demonstrates that transient strain generation in InGaN/GaN MQWs is correlated with electromagnetic THz generation, and both types of emission find their origin in ultrafast dynamical screening of the built-in piezoelectric field in the MQWs. The measured spectral intensity of the detected Brillouin signal corresponds to a maximum strain amplitude of generated acoustic pulses of 2%. This value coincides with the static lattice-mismatch-induced strain in In0.2Ga0.8N/GaN, demonstrating the total release of static strain in MQWs via impulsive THz acoustic emission. This confirms the ultrafast dynamical screening mechanism in MQWs as a highly efficient method for impulsive strain generatio

IDLaS-NL – A platform for running customized studies on individual differences in Dutch language skills via the internet

We introduce the Individual Differences in Language Skills (IDLaS-NL) web platform, which enables users to run studies on individual differences in Dutch language skills via the internet. IDLaS-NL consists of 35 behavioral tests, previously validated in participants aged between 18 and 30 years. The platform provides an intuitive graphical interface for users to select the tests they wish to include in their research, to divide these tests into different sessions and to determine their order. Moreover, for standardized administration the platform provides an application (an emulated browser) wherein the tests are run. Results can be retrieved by mouse click in the graphical interface and are provided as CSV-file output via email. Similarly, the graphical interface enables researchers to modify and delete their study configurations. IDLaS-NL is intended for researchers, clinicians, educators and in general anyone conducting fundamental research into language and general cognitive skills; it is not intended for diagnostic purposes. All platform services are free of charge. Here, we provide a description of its workings as well as instructions for using the platform. The IDLaS-NL platform can be accessed at www.mpi.nl/idlas-nl

Energiebesparing mobiele belichting roos

Over mobiele belichting wordt al jarenlang op verschillende manieren gedacht: enerzijds zou het een manier zijn om lage lichtintensiteiten goed te verdelen over het gewas, anderzijds zou het een manier zijn om energie te besparen, doordat met minder lampen hetzelfde groei-effect werd verwacht. De ‘bewijzen’ van meerproductie onder mobiel licht, vergeleken met dezelfde of een hogere lichtsom waren alleen afkomstig uit praktijkproeven. Een echte fysiologische verklaring voor de vermeende effecten van mobiel licht is nooit gegeven en getoetst. Eén van de theorieën veronderstelt een beter gebruik van het licht (daglicht én assimilatielicht) doordat er af en toe een lichtpuls van hogere intensiteit de planten raakt. Ook zou het op gang komen van de fotosynthese tijdens de lichtpuls beter zijn dan bij continue belichting, zodat wanneer het daglicht fluctueert, de fotosynthese sneller op gang komt in de lichte perioden. Een eventuele betere regulatie van de opening van de huidmondjes (waar de CO2 door naar binnen moet) is ook genoemd. Om te bepalen of er positieven effecten van mobiele belichting zijn en of ze te verklaren zijn uit de eigenschappen van de fotosynthese is een proef met roos uitgevoerd. In deze proef is gekozen voor de zogenaamde ‘lange slag’ mobiele belichting. Dat wil zeggen dat de lampen een lange weg afleggen boven het gewas (in dit project ca 10 meter) en dat de lichtintensiteit tussen twee lichtpulsen in heel laag of nihil is. Ook is er geen achtergrondbelichting van vaste assimilatiebelichting bij de mobiele belichting. De lichtintensiteit voor de planten onder mobiele lampen varieert ‘s nachts daardoor van heel hoog tot nul. In de rozenpraktijk wordt ondertussen vooral belicht met ‘korte slag’ belichting, waar de weg van de lampen meestal van poot tot poot is, dus 4 à 5 meter, en waarbij er wél achtergrondbelichting is van vaste lampen. Deze planten ondervinden dus wel een wisselende lichtintensiteit, maar ‘s nachts wordt de lichtintensiteit nooit nul. Te verwachten is dat de fysiologische verschillen tussen mobiele en vaste belichting bij een lange-slag belichting groter zijn dan bij een korte-slag belichting

A New Mixed-Backbone Oligonucleotide against Glucosylceramide Synthase Sensitizes Multidrug-Resistant Tumors to Apoptosis

Enhanced ceramide glycosylation catalyzed by glucosylceramide synthase (GCS) limits therapeutic efficiencies of antineoplastic agents including doxorubicin in drug-resistant cancer cells. Aimed to determine the role of GCS in tumor response to chemotherapy, a new mixed-backbone oligonucleotide (MBO-asGCS) with higher stability and efficiency has been generated to silence human GCS gene. MBO-asGCS was taken up efficiently in both drug-sensitive and drug-resistant cells, but it selectively suppressed GCS overexpression, and sensitized drug-resistant cells. MBO-asGCS increased doxorubicin sensitivity by 83-fold in human NCI/ADR-RES, and 43-fold in murine EMT6/AR1 breast cancer cells, respectively. In tumor-bearing mice, MBO-asGCS treatment dramatically inhibited the growth of multidrug-resistant NCI/ADR-RE tumors, decreasing tumor volume to 37%, as compared with scrambled control. Furthermore, MBO-asGCS sensitized multidrug-resistant tumors to chemotherapy, increasing doxorubicin efficiency greater than 2-fold. The sensitization effects of MBO-asGCS relied on the decreases of gene expression and enzyme activity of GCS, and on the increases of C18-ceramide and of caspase-executed apoptosis. MBO-asGCS was accumulation in tumor xenografts was greater in other tissues, excepting liver and kidneys; but MBO-asGCS did not exert significant toxic effects on liver and kidneys. This study, for the first time in vivo, has demonstrated that GCS is a promising therapeutic target for cancer drug resistance, and MBO-asGCS has the potential to be developed as an antineoplastic agent