Dimension-adaptive bounds on compressive FLD Classification

Efficient dimensionality reduction by random projections (RP) gains popularity, hence the learning guarantees achievable in RP spaces are of great interest. In finite dimensional setting, it has been shown for the compressive Fisher Linear Discriminant (FLD) classifier that forgood generalisation the required target dimension grows only as the log of the number of classes and is not adversely affected by the number of projected data points. However these bounds depend on the dimensionality d of the original data space. In this paper we give further guarantees that remove d from the bounds under certain conditions of regularity on the data density structure. In particular, if the data density does not fill the ambient space then the error of compressive FLD is independent of the ambient dimension and depends only on a notion of ‘intrinsic dimension'

Wavelet feature extraction and genetic algorithm for biomarker detection in colorectal cancer data

Biomarkers which predict patient’s survival can play an important role in medical diagnosis and treatment. How to select the significant biomarkers from hundreds of protein markers is a key step in survival analysis. In this paper a novel method is proposed to detect the prognostic biomarkers ofsurvival in colorectal cancer patients using wavelet analysis, genetic algorithm, and Bayes classifier. One dimensional discrete wavelet transform (DWT) is normally used to reduce the dimensionality of biomedical data. In this study one dimensional continuous wavelet transform (CWT) was proposed to extract the features of colorectal cancer data. One dimensional CWT has no ability to reduce dimensionality of data, but captures the missing features of DWT, and is complementary part of DWT. Genetic algorithm was performed on extracted wavelet coefficients to select the optimized features, using Bayes classifier to build its fitness function. The corresponding protein markers were located based on the position of optimized features. Kaplan-Meier curve and Cox regression model 2 were used to evaluate the performance of selected biomarkers. Experiments were conducted on colorectal cancer dataset and several significant biomarkers were detected. A new protein biomarker CD46 was found to significantly associate with survival time

Protecting Free-Living Dormice: Molecular Identification of Cestode Parasites in Captive Dormice (Muscardinus avellanarius) Destined for Reintroduction

The success of any population translocation programme relies heavily on the measures implemented to control and monitor the spread of disease. Without these measures, programmes run the risk of releasing immunologically naïve species or, more dangerously, introducing novel infectious agents to native populations. As a precaution, a reintroduction programme for the common or hazel dormouse, Muscardinus avellanarius, in England screens dormice before release following captive breeding. Using PCR sequencing of a range of genes, we tested whether the same species of tapeworm(s) were present in captive and free-living dormice. Whilst only Rodentolepis straminea were identified in free-living dormice, cestode ova found in a captive individual produced a molecular match closely related to Hymenolepis microstoma and a previously unrecorded Rodentolepis species. To prevent putting at risk the free-living population, we recommended the continued treatment of dormice showing tapeworm infection before release. Our work demonstrates how molecular techniques can be used to inform reintroduction programmes, reduce risk from disease and increase chances of reintroduction success

Total loss of MHC class I is an independent indicator of good prognosis in breast cancer

Tumours can be recognised by CTL and NK cells. CTL recognition depends on expression of MHC Class I loaded with peptides from tumour antigens. In contrast, loss of MHC Class I results in NK activation. In our study a large set of samples from patients with primary operable invasive breast cancer was evaluated for the expression of MHC Class I heavy and light by immunohistochemical staining of 439 breast carcinomas in a tissue microarray. Forty-seven percent (206 of 439) of breast carcinomas were considered negative for HLA Class I heavy chain (HC10), whereas lack of anti-β2m-antibody staining was observed in 39% (167 of 424) of tumours, with only 3% of the β2m-negative tumours expressing detectable HLA Class I heavy chain. Correlation with patient outcome showed direct relationship between patient survival and HLA-negative phenotype (log rank = 0.004). A positive relationship was found between the intensity of expression of MHC Class I light and heavy chains expression and histological grade of invasive tumour (p < 0.001) and Nottingham Prognostic Index (p < 0.001). To investigate whether HLA Class I heavy and light chains expression had independent prognostic significance, Cox multivariate regression analysis, including the parameters of tumour size, lymph node stage, grade and intensity of HC10 and anti-β2m staining, was carried out. In our analysis, lymph node stage (p < 0.001), tumour grade (p = 0.005) and intensity of MHC Class I light and heavy chains expression were shown to be independent prognostic factors predictive of overall survival (p-values HC10 = 0.047 and β2m = 0.018)

Dynamics of the solar chromosphere. V. High-frequency modulation in ultraviolet image sequences from TRACE

We search for signatures of high-frequency oscillations in the upper solar photosphere and low chromosphere in the context of acoustic heating of outer stellar atmospheres. We use ultraviolet image sequences of a quiet center-disk area from the Transition Region and Coronal Explorer (TRACE) mission which were taken with strict cadence regularity. The latter permits more reliable high-frequency diagnosis than in earlier work. Spatial Fourier power maps, spatially averaged coherence and phase-difference spectra, and spatio-temporal k-f decompositions all contain high-frequency features that at first sight seem of considerable intrinsic interest but actually are more likely to represent artifacts of different nature. Spatially averaged phase difference measurement provides the most sensitive diagnostic and indicates the presence of acoustic modulation up to f=20 mHz (periods down to 50 seconds) in internetwork areas.Comment: 9 pages, 8 figure

Ferromagnetic resonance of patterned chromium dioxide thin films grown by selective area chemical vapour deposition

This is the final version of the article. Available from the American Institute of Physics via the DOI in this record.A selective area chemical vapour deposition technique has been used to fabricate continuous and patterned epitaxial CrO2 thin films on (100)-oriented TiO2 substrates. Precessional magnetization dynamics were stimulated both electrically and optically, and probed by means of time-resolved Kerr microscopy and vector network analyser ferromagnetic resonance techniques. The dependence of the precession frequency and the effective damping parameter upon the static applied magnetic field were investigated. All films exhibited a large in-plane uniaxial anisotropy. The effective damping parameter was found to exhibit strong field dependence in the vicinity of the hard axis saturation field. However, continuous and patterned films were found to possess generally similar dynamic properties, confirming the suitability of the deposition technique for fabrication of future spintronic devices

Biodegradation of textile azo dyes by a facultative Staphylococcus arlettae strain VN-11 using a sequential microaerophilic/aerobic process

A facultative Staphylococcus arlettae bacterium, isolated from an activated sludge process in a textile industry, was able to successfully decolourize four different azo dyes under microaerophilic conditions (decolourization percentage >97%). Further aeration of the decolourized effluent was performed to promote oxidation of the degradation products. The degradation products were characterized by FT-IR and UV–vis techniques and their toxicity with respect to Daphnia magna was measured. The amine concentrations as well as the total organic carbon (TOC) levels were monitored during the biodegradation process. The presence of aromatic amine in the microaerophilic stage and its absence in the aerobic stage indicated the presence of azoreductase activity and an oxidative biodegradation process, respectively. TOC reduction was ∼15% in the microaerophilic stage and ∼70% in the aerobic stage. The results provided evidence that, using a single Staphylococcus arlettae strain in the same bioreactor, the sequential microaerophilic/aerobic stages were able to form aromatic amines by reductive break-down of the azo bond and to oxidize them into non-toxic metabolites.The authors would like to thank the Portuguese Foundation of Science and Technology (FCT) for providing the grant to Andrea Zille (SFRH/BPD/24238/2005), and the Brazilian Foundation for the Coordination of the Improvement of University Graduates of the Ministry of Education (CAPES) and the National Research Counsel (CNPq) for providing the grants to Elisangela Franciscon

Linear optical properties of one-dimensional Frenkel exciton systems with intersite energy correlations

We analyze the effects of intersite energy correlations on the linear optical properties of one-dimensional disordered Frenkel exciton systems. The absorption line width and the factor of radiative rate enhancement are studied as a function of the correlation length of the disorder. The absorption line width monotonously approaches the seeding degree of disorder on increasing the correlation length. On the contrary, the factor of radiative rate enhancement shows a non-monotonous trend, indicating a complicated scenario of the exciton localization in correlated systems. The concept of coherently bound molecules is exploited to explain the numerical results, showing good agreement with theory. Some recent experiments are discussed in the light of the present theory.Comment: 18 pages, 3 figues, REVTeX, to appear in Physical Review