Large-Scale Assessment of a Fully Automatic Co-Adaptive Motor Imagery-Based Brain Computer Interface

In the last years Brain Computer Interface (BCI) technology has benefited from the development of sophisticated machine leaning methods that let the user operate the BCI after a few trials of calibration. One remarkable example is the recent development of co-adaptive techniques that proved to extend the use of BCIs also to people not able to achieve successful control with the standard BCI procedure. Especially for BCIs based on the modulation of the Sensorimotor Rhythm (SMR) these improvements are essential, since a not negligible percentage of users is unable to operate SMR-BCIs efficiently. In this study we evaluated for the first time a fully automatic co-adaptive BCI system on a large scale. A pool of 168 participants naive to BCIs operated the co-adaptive SMR-BCI in one single session. Different psychological interventions were performed prior the BCI session in order to investigate how motor coordination training and relaxation could influence BCI performance. A neurophysiological indicator based on the Power Spectral Density (PSD) was extracted by the recording of few minutes of resting state brain activity and tested as predictor of BCI performances. Results show that high accuracies in operating the BCI could be reached by the majority of the participants before the end of the session. BCI performances could be significantly predicted by the neurophysiological indicator, consolidating the validity of the model previously developed. Anyway, we still found about 22% of users with performance significantly lower than the threshold of efficient BCI control at the end of the session. Being the inter-subject variability still the major problem of BCI technology, we pointed out crucial issues for those who did not achieve sufficient control. Finally, we propose valid developments to move a step forward to the applicability of the promising co-adaptive methods.     

Genetic differentiation and trade among populations of peach palm (Bactris gasipaes Kunth) in the Peruvian Amazon—implications for genetic resource management

Peach palm (Bactris gasipaes Kunth) is cultivated for fruit and heart of palm, and is an important component of agroforestry systems in the Peruvian Amazon. In this study, AFLP was used to compare genetic diversity among domesticated populations along the Paranapura and Cuiparillo rivers, which are managed by indigenous and colonist farming communities, respectively. Gene diversity was 0.2629 for the populations in indigenous communities and 0.2534 in colonist communities. Genetic differentiation among populations (G_st) was 0.0377–0.0416 (P<0.01) among populations along both rivers. There was no relation between genetic differentiation and the geographical location of populations along the rivers. Since natural seed dispersal by birds and rodents is thought to occur only across relatively short distances (100–200 m), it is likely that exchange of material by farmers and commercial traders is responsible for most of the long-distance (over more than 20 km) gene flow among populations along the two rivers studied. This exchange of material may be important to counteract the effects of selection as well as genetic drift in small groups of trees in farmers fields, much as in a metapopulation, and may account for the weak genetic differentiation between the two rivers (G_st=0.0249, P<0.01). A comparison with samples from other landraces in Peru and Brazil showed the existence of an isolation-by-distance structure up to 3,000 km, consistent with gene flow on a regional scale, likely mediated by trade in the Amazon Basin. Results are discussed with regard to practical implications for the management of genetic resources with farming communities.Electronic Supplementary Material Supplementary material is available in the online version of this article at Communicated by H.F. Linskens     

AMP1 and MP antagonistically regulate embryo and meristem development in Arabidopsis

AUXIN RESPONSE FACTOR (ARF)-mediated signaling conveys positional information during embryonic and postembryonic organogenesis and mutations in MONOPTEROS (MP/ARF5) result in severe patterning defects during embryonic and postembryonic development. Here we show that MP patterning activity is largely dispensable when the presumptive carboxypeptidase ALTERED MERISTEM PROGRAM 1 (AMP1) is not functional, indicating that MP is primarily necessary to counteract AMP1 activity. Closer inspection of the single and double mutant phenotypes reveals antagonistic influences of both genes on meristematic activities throughout the Arabidopsis life cycle. In the absence of MP activity, cells in apical meristems and along the paths of procambium formation acquire differentiated identities and this is largely dependent on differentiation-promoting AMP1 activity. Positions of antagonistic interaction between MP and AMP1 coincide with MP expression domains within the larger AMP1 expression domain. These observations suggest a model in which auxin-derived positional information through MP carves out meristematic niches by locally overcoming a general differentiation-promoting activity involving AMP1.     

Intrinsic Protein Fluorescence Interferes with Detection of Tear Glycoproteins in SDS-Polyacrylamide Gels Using Extrinsic Fluorescent Dyes

Intrinsic protein fluorescence may interfere with the visualization of proteins after SDS-polyacrylamide electrophoresis. In an attempt to analyze tear glycoproteins in gels, we ran tear samples and stained the proteins with a glycoprotein-specific fluorescent dye. The fluorescence detected was not limited to glycoproteins. There was strong intrinsic fluorescence of proteins normally found in tears after soaking the gels in 40% methanol plus 1-10% acetic acid and, to a lesser extent, in methanol or acetic acid alone. Nanograms of proteins gave visible native fluorescence and interfere with extrinsic fluorescent dye detection. Poly-L-lysine, which does not contain intrinsically fluorescent amino acids, did not fluoresce.     

Adaptive on-line classification for EEG-based brain computer interfaces with AAR parameters and band power estimates.

We present the result of on-line feedback Brain Computer Interface experiments using adaptive and non-adaptive feature extraction methods with an on-line adaptive classifier based on Quadratic Discriminant Analysis. Experiments were performed with 12 na?ve subjects, feedback was provided from the first moment and no training sessions were needed. Experiments run in three different days with each subject. Six of them received feedback with Adaptive Autoregressive parameters and the rest with logarithmic Band Power estimates. The study was done using single trial analysis of each of the sessions and the value of the Error Rate and the Mutual Information of the classification were used to discuss the results. Finally, it was shown that even subjects starting with a low performance were able to control the system in a few hours: and contrary to previous results no differences between AAR and BP estimates were found.     

Novel GHRH antagonists suppress the growth of human malignant melanoma by restoring nuclear p27 function

Malignant melanoma is the deadliest form of skin cancer; the treatment of advanced and recurrent forms remains a challenge. It has recently been reported that growth hormone-releasing hormone (GHRH) receptor is involved in the pathogenesis of melanoma. Therefore, we investigated the effects of our new GHRH antagonists on a human melanoma cancer cell line. Antiproliferative effects of GHRH antagonists, MIA-602, MIA-606 and MIA-690, on the human melanoma cell line, A-375, were studied in vitro using the MTS assay. The effect of MIA-690 (5 μg/day 28 d) was further evaluated in vivo in nude mice bearing xenografts of A-375. Subcellular localization of p27 was detected with Western blot and immunofluorescent staining. MIA-690 inhibited the proliferation of A-375 cells in a dose-dependent manner (33% at 10 μM, and 19.2% at 5 μM, P < 0 .05 vs. control), and suppressed the growth of xenografted tumors by 70.45% (P < 0.05). Flow cytometric analysis of cell cycle effects following the administration of MIA-690 revealed a decrease in the number of cells in G2/M phase (from 19.7% to 12.9%, P < 0.001). Additionally, Western blot and immunofluorescent studies showed that exposure of A-375 cells to MIA-690 triggered the nuclear accumulation of p27. MIA-690 inhibited tumor growth in vitro and in vivo, and increased the translocation of p27 into the nucleus thus inhibiting progression of the cell cycle. Our findings indicate that patients with malignant melanoma could benefit from treatment regimens, which combine existing chemotherapy agents and novel GHRH-antagonists.     

An essential saccharide binding domain for the mAb 2C7 established for Neisseria gonorrhoeae LOS by ES-MS and MSn

A study of bacterial surface oligosaccharides were investigated among different strains of Neisseria gonorrhoeae to correlate structural features essential for binding to the MAb 2C7. This epitope is widely expressed and conserved in gonococcal isolates, characteristics essential to an effective candidate vaccine antigen. Sample lipooligosaccharides (LOS), was prepared by a modification of the hot phenol-water method from which de-O-acetylated LOS and oligosaccharide (OS) components were analyzed by ES-MS-CID-MS and ES-MSnin a triple quadrupole and an ion trap mass spectrometer, respectively. Previously documented natural heterogeneity was apparent from both LOS and OS preparations which was admixed with fragments induced by hydrazine and mild acid treatment. Natural heterogeneity was limited to phosphorylation and antenni extensions to the alpha-chain. Mild acid hydrolysis to release OS also hydrolyzed the beta(1-->6) glycosidic linkage of lipid A. OS structures were determined by collisional and resonance excitation combined with MS and multistep MSn which provided sequence information from both neutral loss, and nonreducing terminal fragments. A comparison of OS structures, with earlier knowledge of MAb binding, enzyme treatment, and partial acid hydrolysis indicates a generic overlapping domain for 2C7 binding. Reoccurring structural features include a Hepalpha(1-->3)Hepbeta(1-->5)KDO trisaccharide core branched on the nonreducing terminus (Hep-2) with an alpha(1-->2) linked GlcNAc (gamma-chain), and an alpha-linked lactose (beta-chain) residue. From the central heptose (Hep-1), a beta(1-->4) linked lactose (alpha-chain), moiety is required although extensions to this residue appear unnecessary.      

Novel Cyanobacterial Diversity Found in Costa Rican Thermal Springs Associated with Rincon de la Vieja and Miravalles Volcanoes: A Polyphasic Approach

Central America is one of the most important biodiversity hot spots in the world, and Costa Rican microbial communities from thermal springs are the best characterized in the isthmus. Miravalles is an inactive quaternary stratovolcano, and the Rincón de la Vieja is a unique active volcano, in whose slopes diverse hydrothermal springs, such as Las Lilas, are located. These springs harbor extensive microbial mats, whose diversity has been studied. Based on their importance as primary producers, in this study we focused on cultured cyanobacterial diversity from two geothermal environments of northern Costa Rica. Several cultural, molecular and taxonomic techniques were employed to maximize the results of a polyphasic approach. Sample collection sites were physicochemically described, and strains were isolated and characterized by light and electron microscopy. Phylogenetic analysis was performed using 16S rRNA gene sequences and amplified ribosomal DNA restriction analysis (ARDRA). Fifty‐six phylotypes were isolated and classified into 21 morphotypes and identified in 14 genera, some of them might be new species within these genera. Furthermore, according to phylogenetic analysis, there are three possible new genera in our collection. Miravalles and Las Lilas thermal springs are reservoirs of novel phylogeographic lineages of phototrophic microorganisms. This study is the first report of strains that belong to the genera Gloeocapsa, Stanieria, Microseira, Klisinema and Oculatella isolated from thermal springs and growing at temperatures above 50°C. We also obtained isolates assigned to Synechococcus, Leptolyngbya spp., and Fischerella, which are considered typical strains in these environments.