Photoperiodic Response of Abrostola asclepiadis (Lepidoptera: Noctuidae), a Candidate Biological Control Agent for Swallow-worts (Vincetoxicum, Apocynaceae)

A biological control program is in development for two swallow-wort species (Vincetoxicum, Apocynaceae), European vines introduced into northeastern North America. One candidate agent is the defoliator Abrostola asclepiadis (Denis and Schiffermüller) (Lepidoptera: Noctuidae). The moth reportedly has up to two generations in parts of its native range. We assessed the potential multivoltinism of Russian and French populations of the moth by rearing them under constant and changing photoperiods, ranging from 13:11 to 16:8 hour (L:D). The French population was also reared outdoors under naturally-changing day lengths at a latitude similar to northern New York State. Less than six adult moths emerged, with one exception, for any photoperiod treatment. We expect A. asclepiadis to be univoltine if it were to be released into North America, limiting its potential impact on swallow-worts. It should therefore be given a lower priority for release

Propagation model for the Land Mobile Satellite channel in urban environments

This paper presents the major characteristics of a simulation package capable of performing a complete narrow and wideband analysis of the mobile satellite communication channel in urban environments for any given orbital configuration. The wavelength-to-average urban geometrical dimension ratio has required the use of the Geometrical Theory of Diffraction (GTD). For the RF frequency range, the model has been designed to be (1 up to 60 GHz) extended to include effects of non-perfect conductivity and surface roughness. Taking advantage of the inherent capabilities of such a high frequency method, we are able to provide a complete description of the electromagnetic field at the mobile terminal. Using the information made available at the ray-tracer and GTD solver outputs, the Land Mobile Satellite (LMS) urban model can also give a detailed description of the communication channel in terms of power delay profiles, Doppler spectra, channel scattering functions, and so forth. Statistical data, e.g. cumulative distribution functions, level crossing rates or distributions of fades are also provided. The user can access the simulation tool through a Design-CAD user-friendly interface by means of which she can effectively design her own urban layout and run consequently all the envisaged routines. The software is optimized in its execution time so that numerous runs can be achieved in a considerably short time

The three-dimensional wake behind an obstacle on a flat plate

Three dimensional incompressible wake behind blunt obstacle located at leading edge of flat plat

Genetic drift at expanding frontiers promotes gene segregation

Competition between random genetic drift and natural selection plays a central role in evolution: Whereas non-beneficial mutations often prevail in small populations by chance, mutations that sweep through large populations typically confer a selective advantage. Here, however, we observe chance effects during range expansions that dramatically alter the gene pool even in large microbial populations. Initially well-mixed populations of two fluorescently labeled strains of Escherichia coli develop well-defined, sector-like regions with fractal boundaries in expanding colonies. The formation of these regions is driven by random fluctuations that originate in a thin band of pioneers at the expanding frontier. A comparison of bacterial and yeast colonies (Saccharomyces cerevisiae) suggests that this large-scale genetic sectoring is a generic phenomenon that may provide a detectable footprint of past range expansions.Comment: Please visit http://www.pnas.org/content/104/50/19926.abstract for published articl

Measurement of Dielectric Suppression of Bremsstrahlung

In 1953, Ter-Mikaelian predicted that the bremsstrahlung of low energy photons in a medium is suppressed because of interactions between the produced photon and the electrons in the medium. This suppression occurs because the emission takes place over on a long distance scale, allowing for destructive interference between different instantaneous photon emission amplitudes. We present here measurements of bremsstrahlung cross sections of 200 keV to 20 MeV photons produced by 8 and 25 GeV electrons in carbon and gold targets. Our data shows that dielectric suppression occurs at the predicted level, reducing the cross section up to 75 percent in our data.Comment: 11 pages, format is postscript file, gzip-ed, uuencode-e

In-depth analysis of the Naming Game dynamics: the homogeneous mixing case

Language emergence and evolution has recently gained growing attention through multi-agent models and mathematical frameworks to study their behavior. Here we investigate further the Naming Game, a model able to account for the emergence of a shared vocabulary of form-meaning associations through social/cultural learning. Due to the simplicity of both the structure of the agents and their interaction rules, the dynamics of this model can be analyzed in great detail using numerical simulations and analytical arguments. This paper first reviews some existing results and then presents a new overall understanding.Comment: 30 pages, 19 figures (few in reduced definition). In press in IJMP

Standardised surface electromyography allows effective submental muscles assessment

The aims of this pilot study were to evaluate: (i) the reproducibility and variability of an electromyographical protocol developed for the assessment of submental muscles (SM) (ii) to apply the new protocol to maximal teeth clenching, a simple and largely studied static task in order to quantify the relative contribution of submental muscles. In 20 healthy subjects, aged 19-35years, surface electromyography of SM, masseter (MM) and anterior temporalis (TA) muscles was performed during maximal voluntary clenching (MVC) with and without cotton rolls and the pushing of the tongue against the palate. Clenching on cotton rolls and pushing the tongue against the palate were used to standardise respectively MM and TA, and SM muscular potentials. The exercises were repeated in two appointments (T1-T2); submental muscles standardisation was also repeated twice (A-B) in each session to assess repeatability. Symmetry and activity were calculated for each couple of muscles. A two-way analysis of variance was computed for SM: no Factor 1 (T1 vs T2) or Factor 2 (A vs B) or F1 7F2 significant effects were found. SM recruitment was 31% of the maximal activity, with symmetry values larger than 80%. In conclusion, standardised electromyography allows a reliable assessment of Submental muscles activity

How to make experimental economics research more reproducible: lessons from other disciplines and a new proposal

Efforts in the spirit of this special issue aim at improving the reproducibility of experimental economics, in response to the recent discussions regarding the “research reproducibility crisis.” We put this endeavour in perspective by summarizing the main ways (to our knowledge) that have been proposed – by researchers from several disciplines – to alleviate the problem. We discuss the scope for economic theory to contribute to evaluating the proposals. We argue that a potential key impediment to replication is the expectation of negative reactions by the authors of the individual study, and suggest that incentives for having one’s work replicated should increase

Gene Modulation by Peptide Nucleic Acids (PNAs) Targeting microRNAs (miRs)

Since non-viral gene therapy was developed and employed in different in vitro and in vivo experimental systems as an effective way to control and modify gene expression, RNA has been considered as a molecular target of great relevance (Li &Huang, 2008, López-Fraga et al., 2008). In combination with standard chemotherapy, the siRNA therapy can reduce the chemoresistance of certain cancers, demonstrating its potential for treating many malignant diseases. Examples of RNA sequences to be targeted for therapeutic applications are mRNAs coding oncoproteins or RNA coding anti-apoptotic proteins for the development of anti-cancer therapy. In the last years, progresses in molecular biology have allowed to identify many genes Coding for small non coding RNA molecules, microRNA (miRNAs or miRs), able to regulate gene expression at the translation level (Huang et al., 2008, Shrivastava & Shrivastava, 2008, Sahu et al. 2007, Orlacchio et al., 2007, Williams et al., 2008, Papagiannakopoulos & Kosik, 2008). Accordingly, an increasing number of reports associate the changed expression with specific phenotypes and even with pathological conditions (Garzon & Croce, 2008, Mascellani et al., 2008, Sontheimer & Carthew, 2005, Filipowicz et al., 2005, Alvarez-Garcia & Miska, 2005). Interestingly, microRNAs play a double role in cancer, behaving both as oncogenes or tumor suppressor genes. In general, miRs promoting cancer targets mRNA coding for tumor-suppression proteins, while microRNAs exhibiting tumor-suppression properties usually target mRNAs coding oncoproteins. MicroRNAs which have been demonstrated to play a crucial role in the initiation and progression of human cancer are defined as oncogenic miRNAs (oncomiRs) (Cho, 2007). The oncomiR expression profiling of human malignancies has also identified a number of diagnostic and prognostic cancer signals (Cho, 2007, Lowery et al., 2008). Moreover, microRNAs have been firmly demonstrated to be involved in cancer metastasis (metastamiRs). Examples of metastasis-promoting microRNAs are, miR-10b (Calin et al., 2006), miR-373 and - 520c (Woods et al., 2007), miR-21, -143 and -182 (Hayashita et al., 2005; Si et al., 2007; Zhu et al.,2007). Reviews on metastamiR has been recently published Hurst et al. (Hurst et al. 2009, Edmonds et al. 2009). Reviews on metastamiRs has been recently published by Hurst et al